Button type package humidity indicator



A g- 3 1955 I w. c. BLINN 2,716,338

' BUTTON TYPE PACKAGE HUMIDITY INDICATOR Filed April 8, 1954 IN V EN TOR.

Zi Z/o/"d C 528 2777. BY

HT-roR/vEy.

United States Patent BUTTON TYPE PACKAGE HUMIDITY INDICATOR Welford C. Blinn, Colton, Calif.

Application April 8, 1954, Serial No. 421,891

2 Claims. (Cl. 73-73) This invention relates to package humidity indicators .5

and more specifically to an indicator of the button type.

A primary object of the invention is to provide a humidity indicator which forms an integral part of a closed container, or a moistureproof bag, and permits the observer to note the humidity of the air within the container.

Another object is to provide a card having a number of spots of chemical matter impregnated therein so that each spot may indicate a separate humidity.

A further object is the provision of a humidity indicator of a stable nature which will indicate a critical range of humidities within a closed container so as to prevent material in storage and transit from rusting or otherwise deterioriating due to leakage.

Another object is to provide a humidity indicator having an inexpensive window through which the chemical spot indicators may be seen without having to break the container seal.

A further object is to provide a device having a window which does not project materially so as to permit stacking of containers during transit and storage.

An important object is to provide a button type device that is reusable and one that can be attached to a package without the use of glue, grommets, or of parts having expensive machined threads or fittings that must be machined into the package at the time of manufacture.

Another object is to provide a window made of moistureproof materials that are low in cost and readily applied with hand pressure or a standard tool.

Other objects and advantages will become apparent from the following description and drawings, in which:

Fig. 1 is a perspective view of a package withthe improved button type humidity indicator secured thereto.

Fig. 2 is an enlarged plan view of the indicator.

Fig. 3 is a sectional view taken on line 33 of Fig. 2.

Fig. 4 is a bottom plan view of the device shown in Fig. 3.

Fig. 5 is a sectional view taken on line 55 of Fig. 3.

Fig. 6 is a plan view of a card showing a modified form of chemical spots used in the device.

As shown in the drawings the numeral 10 designates a closed package having a hermetically sealed lid 10a. Located inside the package is a product or the like 1%, to be protected from rust and deterioriation by the use of a conventional desiccant 100. An aperture 11 is punched or cut into the package at a suitable place and my improved form of button humidity indicator is placed therein to form a moisturetight and integral part of the package.

Aligned with the aperture 11 and located within the package 10 (see Fig. 3), is a lock nut 14, having internal threads 15 and a flange 16. A gasket 17, preferably made of rubber, is placed between the flange 16 and the lid 10a, and a hollow button 18, having a tubular shank with external threads 19 is inserted through the aperture 11 and screwed into the lock nut 14, said button having a flange '21 around its outer 'end which serves to clamp the lid 10a between the Washer '17 and flange 16 to render the package leakproof. I

As shown "in Figs. 3, 4 and 5, the button 18has web 18a to reinforce the button against an internal pressure :c'ffive pounds per square inch for an indefinite time. The flange 21 of button 18 is provided with a raised portion '23 surrounding a recess or central countersink 24 adapted to receive an indicating card '25. The button 18 has a'ir passages '26 open from the inside of the package and leading to the under surface of the card'ZS.

To insure that the major portion of the under surface of the card 25 is exposed to the air in the package, the button 18 is countersunk at 28 as shown in Fig. 2. The upper surface of the card 25 is provided with a plurality of chemical spots which are impregnated thereinto. The card may be made of blotting paper or the like.

When installed, the button humidity indicator forms a moisturetight and integral part of the package, and permits the humidity of the air within to be observed by noting the color of the chemical spots 30 impregnated on the card 25, each spot indicating a separate humidity.

As shown in Fig. 2, the numerals 32 are located on the spots 30, each numeral serving to indicate a related humidity condition. The printed matter 33 also serves to advise the observer regarding the humidity conditions within the package, as related to the spots 30.

To enclose and protect the card 25, a transparent cover 35 is provided having a dependent flange 36. The flange 36 is mounted in the rabbet 22 of the flange 21 and a solvent or adhesive may be applied with a hypodermic needle or brush to bond the parts together, which is done before the installation of the button 18in said package.

The button 18 and lock nut 14 may be made of metal or like materials, but I prefer to use flexible polystyrene which provides good strength against breakage under impact or strain, and furthermore is moistureproof. The cap 35 is transparent and is made of clear polystyrene. The cap 35 and flange 21 are shown as hexagonal, but any suitable shape may be used.

The form of invention shown in Fig. 6 shows a plurality of chemical spots 39 impregnated on a card 40, the numerals 41 and printed matter 42' serving the same purpose as indicated in Fig. 2.

From the foregoing it is apparent that I have invented a package humidity indicator of the button type that is especially adaptable to small packages. My improved device provides chemical spot indicators that can be easily seen without breaking the seal, and may be secured to the package through a very small hole which is effectively rendered leakproof against a continuous pressure of five pounds per square inch.

My device will register by color change of chemical spots, critical humidity points within almost any type of container now in use and will warn the observer if a leak develops in the package. The device is simple, practical, moistureproof and leakproof.

I reserve the right to make numerous changes in the size, shape and arrangement of the parts without departing from the spirit of the invention, or the scope of the claims.

What I claim is:

1. In a device of the kind described, a unit for mounting in an aperture in the wall of a container, said unit comprising a button, a flange on the button to engage the exterior of the container, said flange having a recess and a rabbet, a card mounted in said recess, the card having chemical spots impregnated therein, a transparent cap mounted in the rabbet of said flange and sealed thereto, and means to secure the said unit to the container in an airtight manner to render the unit leakproof therein, and a transparent cap having around it a flange 1 mounted in said rabbet and sealed thereto to render the unit leakproof, said countersink serving to increase the amount of the cards surface which is exposed to air in communication with the interior of the container.

References Cited in the file of this patent UNITED STATES PATENTS Snelling July 22,

Lindsay Oct. 7,

Clibbon Aug. 3,

Lewis Aug. 5,

FOREIGN PATENTS Germany Dec. 22, 

